In a speech that only 48 hours ago was going to be solely a call to arms, Mr. Obama instead offered a qualified endorsement of a proposal that his own advisers conceded was
rife with risk, given Russia’s steadfast refusal to agree to any previous measures to pressure Syria, its longtime ally.

But administration officials said they were swayed by the level of detail in the Russian proposal, which grew out of an
impromptu conversation between Mr. Obama and President Vladimir V. Putin on the sidelines of a summit meeting in St. Petersburg, Russia, last week.

As money and national attention poured into Colorado, a state of hunters that has been stained by two mass shootings, the races became a symbol of the nation’s bitter fight over gun control, with one side
bolstered by Mayor Michael R. Bloomberg of New York and the other by the National Rifle Association.